全文获取类型
收费全文 | 2193篇 |
免费 | 62篇 |
国内免费 | 22篇 |
专业分类
管理学 | 148篇 |
劳动科学 | 1篇 |
民族学 | 5篇 |
人口学 | 39篇 |
丛书文集 | 82篇 |
理论方法论 | 19篇 |
综合类 | 916篇 |
社会学 | 31篇 |
统计学 | 1036篇 |
出版年
2023年 | 12篇 |
2022年 | 19篇 |
2021年 | 20篇 |
2020年 | 28篇 |
2019年 | 51篇 |
2018年 | 73篇 |
2017年 | 85篇 |
2016年 | 80篇 |
2015年 | 75篇 |
2014年 | 114篇 |
2013年 | 414篇 |
2012年 | 170篇 |
2011年 | 138篇 |
2010年 | 111篇 |
2009年 | 98篇 |
2008年 | 86篇 |
2007年 | 112篇 |
2006年 | 93篇 |
2005年 | 62篇 |
2004年 | 59篇 |
2003年 | 60篇 |
2002年 | 48篇 |
2001年 | 37篇 |
2000年 | 28篇 |
1999年 | 32篇 |
1998年 | 26篇 |
1997年 | 12篇 |
1996年 | 20篇 |
1995年 | 21篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有2277条查询结果,搜索用时 31 毫秒
251.
Richard Woodhouse 《Journal of applied statistics》2006,33(3):241-255
Structural regression attempts to reveal an underlying relationship by compensating for errors in the variables. Ordinary least-squares regression has an entirely different purpose and provides a relationship between error-included variables. Structural model solutions, also known as the errors-in-variables and measurement-error solutions, use various inputs such as the error-variance ratio and x-error variance. This paper proposes that more accurate structural line gradient (coefficient) solutions will result from using the several solutions together as a system of equations. The known data scatter, as measured by the correlation coefficient, should always be used in choosing legitimate combinations of x- and y-error terms. However, this is difficult using equations. Chart solutions are presented to assist users to understand the structural regression process, to observe the correlation coefficient constraint, to assess the impact of their error estimates and, therefore, to provide better quality estimates of the structural regression gradient. 相似文献
252.
在文献[1~4]的基础上,进一步提出产出-完全经济效益传递系数、贡献系数和受益系数,以揭示产出与经济效益的相互联系和数量关系,并在此基础上提出了提高各部门经济效益的主要途径。 相似文献
253.
针对房价收入比指标衡量区域房地产价格与居民收入水平关系中的不足,提出人均住宅有效购买力系数的概念,阐述该指标的优点,并用该指标对1987年以来中国人均住宅有效购买力的变化和截止2004年底37个大中城市人均有效购买力的横向对比做了实证分析,进而探讨了建构中国房地产市场统计指标体系的新思路。 相似文献
254.
文章通过对隶属函数的集中度系数确定的探讨,将模糊数学应用于贝叶斯统计学,从而形成了一种新的假设检验方法. 相似文献
255.
一种多波形雷达信号全数字产生及处理系统 总被引:2,自引:0,他引:2
提出并实现了兼容多种雷达脉压信号的全数字产生及处理系统。其信号包括线性调频信号、非线性调频信号及其多相码、泰勒(Taylor)四相码信号等。利用级联型FIR滤波器IMSA100组成数字复相关脉压网络对多种带宽(带发达5MHz)脉压信号进行实时数字处理;分析了数字方法运用于波形合成中由于DAC零阶保持特性造成的信号频谱高频失真的机理;采用提高DAC转换速率以获得近似理想冲激串取样的方法,产生了多种性能稳定、波形质量高的宽带雷达脉压信号。文中给出了部分模拟与实验结果。 相似文献
256.
Graham R. Wood David J. Saville 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2005,168(1):95-107
Summary. Previously we used the geometry of n -dimensional space to derive the paired samples t -test and its p -value. In the present paper we describe the 'ubiquitous' application of these results to single degree of freedom linear model hypothesis tests. As examples, we derive the p - and t -values for the independent samples t -test, for testing a contrast in an analysis of variance and for testing the slope in a simple linear regression analysis. An angle θ in n -dimensional space is again pivotal in the development of the ideas. The relationships between p , t , θ , F and the correlation coefficient are also described by using a 'statistical triangle'. 相似文献
257.
针对区域产业投入的优化问题,不仅考虑到投入的经济效益,同时也考虑了投入的社会效益和生态效益,综合主观赋权法和客观赋权法,建立熵权系数模型,以确定各产业的最优投入,并举例说明模型的应用. 相似文献
258.
Suppose that the maximum of a random sample from a distribution F(x) may be obtained in each of k equally spaced observation periods. This paper proposes a test to determine the domain of attraction of F(x), and investigates the properties when the sample size is very large and perhaps unknown and k is fixed and small. The test statistic is a function of the spacings between the order statistics based on the sequence of maxima and is suggested by reference to one studied previously when inference was based on the largest k observations of a random sample. A Monte Carlo study shows that the proposed test is more powerful than its main competitor. The test is illustrated by two examples. 相似文献
259.
冯林 《电子科技大学学报(社会科学版)》1987,(2)
本文以样条函数(spline function)作为电磁波Helmholtz方程的近似解,求解了等离子体鞘套的反射系数和透射系数。本文采用的样条函数法具有数学推导和数字计算简单,可适用于任意电子浓度分布的优点,并且计算结果与美国RAM C系列飞行实测数据吻合得比较好。同时,本方法还可用于求解其它不均匀介质中的电波传播问题。 相似文献
260.
A. Brezger L. Fahrmeir A. Hennerfeind 《Journal of the Royal Statistical Society. Series C, Applied statistics》2007,56(3):327-345
Summary. Functional magnetic resonance imaging has become a standard technology in human brain mapping. Analyses of the massive spatiotemporal functional magnetic resonance imaging data sets often focus on parametric or non-parametric modelling of the temporal component, whereas spatial smoothing is based on Gaussian kernels or random fields. A weakness of Gaussian spatial smoothing is underestimation of activation peaks or blurring of high curvature transitions between activated and non-activated regions of the brain. To improve spatial adaptivity, we introduce a class of inhomogeneous Markov random fields with stochastic interaction weights in a space-varying coefficient model. For given weights, the random field is conditionally Gaussian, but marginally it is non-Gaussian. Fully Bayesian inference, including estimation of weights and variance parameters, can be carried out through efficient Markov chain Monte Carlo simulation. Although motivated by the analysis of functional magnetic resonance imaging data, the methodological development is general and can also be used for spatial smoothing and regression analysis of areal data on irregular lattices. An application to stylized artificial data and to real functional magnetic resonance imaging data from a visual stimulation experiment demonstrates the performance of our approach in comparison with Gaussian and robustified non-Gaussian Markov random-field models. 相似文献